Analysis of the effects of coumarin on Lens culinaris Medik by some biochemical parameters using real-time polymerase chain reaction

This study aimed to reveal the effects of coumarin on Lens culinaris Medik. The germinated and ungerminated seed counts of the experimental groups were determined and the EC50 value was calculated by probit analysis. In biochemical studies, catalase and superoxide dismutase enzyme activities were investigated together with lipid peroxidation and hydrogen peroxide quantities. The results demonstrated an increase in the amount of malondialdehyde, a measure of lipid peroxidation, a decrease in the amount of H2O2 and EC50 value in the CAT activity and an increase in the EC50 x 2 value. In real-time PCR analysis, three different genetic expressions related to abiotic stress (CAT, Cu / Zn SOD and Mn SOD gene expression) were examined. It was determined that coumarin caused genotoxic and biochemical damage on L. culinaris.

Survival of weed seeds in cocopeat bricks for hydroponics

In 2007 seeds of 31 species previously unknown in New Zealand were identified in cocopeat imported from Sri Lanka Cocopeat is used as a growing medium for hydroponic vegetable production The aim of this study was to evaluate the viability of weed seeds present in cocopeat over a 12 month growing season Twenty or forty seeds of five representative species were counted into fine mesh bags and inserted into the cocopeat bricks Tomatoes (Lycopersicon esculentum) and capsicums (Capsicum annuum) were grown in the cocopeat with nutrients supplied via a constant trickle of hydroponic nutrient solution After 3 (n4) 6 (n4) and 12 (n8) months seed packets were removed for germination testing which was firstly carried out over 28 days on KNO3soaked blotters after which ungerminated seed was pricked and left for a further 28 days After 12 months 37 and 45 of the grass species Panicum miliaceum and Digitaria sanguinalis respectively germinated while that for the broadleaf species Cleome rutidosperma Mollugo nudicaulis and Amaranthus viridis was 20 48 and 38 respectively Results from the 3 and 6 month samplings were intermediate and show that long term exposure to hydroponic solution did little to reduce the viability of weed seeds found in imported cocopeat

(206) Carbohydrate Compositions and Peroxidase Activity in Whole Seed, Cotyledon, and Embryo Tissues of Cowpea (Vigna unguiculata L. Walp) Cultivars Grown Under Stress Temperatures

Twenty-five cultivars were initially screened for germination at 10 °C, 30 °C, and 40 °C. Four cultivars were chosen for further study for physiological and biochemical characteristics—namely, `Texas Cream 40' (TC-40), which showed ability to germinate at very high (40 °C) and low (10 °C) temperatures; `Black Crowder' (BC), which had acceptably high germination at 40 °C, but reduced germination at 10 °C; and `Mississippi Purple' (MP), which exhibited lower germination at all temperatures tested. The main sugars present in cowpea seed were sucrose, raffinose, and stachyose. Sugar contents were affected by cultivar, type of tissue, and temperature. Sucrose contents were higher in embryo tissue of cultivars with a lower germination percentage, and reduced in the cultivar with a higher germination percentage, suggesting the use of sucrose for germination. Sucrose decreased greatly at 30 °C and increased again at 40 °C. Sucrose “de novo” synthesis was higher at higher temperature. An accumulation of sucrose was evident in embryo tissues of cultivars with reduced ability to germinate at low temperature. Raffinose and stachyose contents were higher in ungerminated seed. In germinated seed, raffinose and stachyose contents were found only in cotyledon tissues at 10 °C. The peroxidase activity was affected by cultivars, type of tissue, and temperature. The highest peroxidase activity was found at low temperature (10 °C) in embryo tissue of the cultivar with the highest germination. The result also suggests that high peroxidase activity was related to ability of seed to germinate at low temperature.

RAPD analysis of seed purity in a commercial hybrid cabbage (Brassica oleracea var. capitata) cultivar

The use of random amplified polymorphic DNA (RAPD) markers for evaluating seed purity in a commercial F1-hybrid cabbage (Brassica oleracea var. capitata) cultivar is demonstrated. Genomic DNA isolated from single ungerminated seed was found to be suitable for RAPD analysis. DNA from F1-hybrid and its parental lines was subjected to RAPD screening with 36 random decamer arbitrary primers. A total of 241 scorable products were observed with 54 (22%) being polymorphic. The RAPD data showed that the parental lines of this commercial cabbage cultivar were not very closely related. Two primers were chosen for purity testing of the F1-hybrid seeds. The sib (inbred seed; seed from self-pollination of parental lines) contamination results obtained by RAPD analysis were comparable to the commonly used grow-out trial and isozyme analysis, hence showing that RAPD analysis can be used for seed purity testing of commercial hybrid cabbage seeds. Key words: Brassica, cabbage, RAPD, seed purity test, F1-hybrid seed.

Proteins Associated with Germination of Cucumber at Various Temperatures

Cucumber (Cucumis sativus L.) seed require soil temperature to be around 20C for efficient germination. This hinders early planting in cool soils. This study was conducted to determine how germinating seed of cucumber cultivars Earlipik 14 and Arkansas Little Leaf at 13.9, 15.6, and 20C in the dark affected protein formation. Seed were removed from moist chambers at 0, 12, 24, 48, 72, 84, 96, 120, and 168 h. Germination, defined as the radicle being at least 5 mm long, was determined at each time. Germinated and ungerminated seed was prepared for polyacrylamide gel electrophoresis. At 20C, 90% to 100% of seed had germinated by 48 h. At 15.6C, 20% to 50% of seed germinated by 168 h, and at 13.9C, ≈2% of seed had germinated by 168 h. For seed incubated at 20C, concentrations of proteins at 70.1 kDa decreased, while those at 37.4, 43.4, and 50 kDa increased after 24 h, which corresponded to formation and elongation of the majority of radicles. These changes were expressed later for seed germinated at 15.6 and 13.9C. Identification of the proteins is being attempted. The importance of these proteins in germination and early development will be discussed.

Germination and Seedling Growth of Sorghum (Sorghum bicolor) Hybrids After Seed Storage with Safeners at Varying Humidities

Laboratory and growth room experiments were conducted to determine effects of CGA-133205, oxabetrinil, and flurazole on grain sorghum hybrids ‘DeKalb 46’ and ‘DeKalb 48’ after the seed were treated with the herbicide safeners and stored for up to 24 wk at various relative humidity levels. Each safener treatment had an adverse effect on grain sorghum seed as reflected by fewer normal seedlings at 4 d when averaged over storage time and relative humidity levels. Flurazole and oxabetrinil increased the number of ungerminated seed of both hybrids, and 0.4 and 0.8 g ai kg–1CGA-133205 increased ungerminated seed of DeKalb 46. At ≥ 8 wk after storage, a reduction in germination was observed for seed treated with flurazole or oxabetrinil compared to seed stored without safener. This reduction also occurred with 0.4 and 0.8 g kg–1CGA-133205, but only at 24 wk after storage. Each safener treatment minimized reduction in seedling shoot fresh weight by herbicides compared to the no-safener check through 24 wk after storage.

SDS–PAGE of seed proteins in Festuca (Poaceae): taxonomic implications

Taxonomically useful descriptors were provided by the banding patterns of seed storage proteins obtained when extracts of bulked, ungerminated seed samples from commercially available North American native species of Festuca were analyzed by sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS–PAGE). The banding patterns for three species of rough fescues (section Breviaristatae Krivot) indicate that although the taxa are closely related, F. campestris Rydb. (2n = 56) does not appear to be an autoploid of either F. altaica Trin. (2n = 28) or F. hallii (Vasey) Piper (2n = 28). A distinct band corresponding to a molecular weight of 57 000 occurred in the seed protein profiles of all native and commercial samples of Festuca L. analyzed. The profile for F. californica Vasey, questionably section Breviaristatae, also has a band at this position, and is very different from that of F. altaica, F. campestris, and F. hallii. Species-specific banding patterns were observed for F. brachyphylla Schultes, F. saximontana Rydb., F. idahoensis Elmer, and F. trachyphylla (Hackel) Krajina (F. ovina L. s.l., F. longifolia Thuill., F. ovina var. duriuscula auct. amer.). The results support the recognition of subgenus Schedonorus (Beauv.) Peter., and sections Breviaristatae Krivot and Festuca. Key words: Poaceae, Festuca, SDS–PAGE seed proteins.

Differential activity of acid phosphatases from the endosperm and haustorium of date palm (Phoenix dactyliferd) seeds

The acid phosphatase (APase) activity in different parts of ungerminated and germinated seeds of date palm (Phoenix dactylifera L.) was investigated by enzyme assays and on polyacrylamide native isoelectric focusing gels. In the ungerminated seed, APase activity was detected in both the endosperm and the embryo, but the activity was greater in the endosperm. During seedling growth, enzyme activity in the developing haustorium and in the digesting endosperm was 10–15 times greater than that in dry seeds. The APases of the endosperm were different from those of the haustorium: (i) the molecular mass of the enzyme from the endosperm was approximately 52 000 while that of the haustorium was approximately 21 500; (ii) the pH optimum of the APases from the haustorium was 5.0, while it was between 5.0 and 6.5 for those of the digesting endosperm; and (iii) the endosperm contained 6 isoenzymes of pI 3.6–4.3, whereas the haustorium contained 14 isoenzymes with pIs ranging from 5.3 to 6.8. These observations suggest that phosphate metabolism in the endosperm is independent of that in the haustorium and that the APases for endosperm phosphate mobilization are not secreted by the embryo or the haustorium, but instead are stored in the endosperm.

Polyploid Distribution and Seed Dormancy in Relation to Provenance Rainfall in the Digitaria milanjiana Complex

Chromosome numbers were counted in 72 accessions in the Digitaria milanjiana complex and 2 of D. macroblephara from contrasting climates in Africa; 18 were diploids, 38 tetraploids, and 18 hexaploids. Higher polyploids were mostly from lower rainfall provenances. Diploids were mostly accessions which had been attributed to other species in pre-1982 classifications but which are now considered to be synonyms of D. milanjiana. Some 29 accessions, including diploids, tetraploids and hexaploids from low-rainfall and high-rainfall provenances at equatorial or near-tropical latitudes were grown and seed was harvested on 2 occasions (Jan. and Mar. 1987). Seed was treated at alternating temp. of 30/25°C or constant 60°C for 0, 2, 6, 10 or 16 weeks and then germinated. Percentage germination increased over time for all accessions, from 1% at harvest to 26% at 16 weeks. Germination was markedly lower in accessions from low-rainfall (14%) than high-rainfall (33% at 16 weeks) provenances. Similarly, percentage germination was lower in hexaploids (16%) than tetraploids (26%) and lower in tetraploids than diploids (38% at 16 weeks). High temp. treatment increased germination percentage but the effect was only marked in accessions with comparatively high levels of germination at low temperatures. Percentage dormancy (estimations based on live but ungerminated seed after germination treatment following 16 weeks at 60°C) was significantly and negatively correlated with rainfall of provenance. It was concluded that seed dormancy in D. milanjiana is related both to polyploidy and rainfall of provenance and that genetic adaptation to arid regions has been associated with polyploidisation and increasing dormancy.

Separation of Pinusbanksiana Lamb. glyceraldehyde 3-phosphate (NAD) dehydrogenase from phenolic-based pigments with affinity chromatography

Glyceraldehyde 3-phosphate (NAD) dehydrogenase was extracted from Pinusbanksiana Lamb, seed and from seedlings up to 12 days old. Enzyme activity in crude extracts of seedlings increased markedly from days 2–8 and then decreased slightly, as indicated by spectrophotometric assay. In contrast, staining of acrylamide gels after disc electrophoresis indicated that catalytically active isozymes were not present in crude extracts at and after day 6. Phenolics greatly increased in extracts from days 0–10 and polymerization of these phenolics apparently lead to binding of the resulting phenolic-based pigment to enzyme. The pigment–enzyme complex demonstrated greatly enhanced electrophoretic movement, in comparison with the individual isozymes, which caused frontal migration of the collective isozymes. Affinity chromatography restored electrophoretic mobility of isozymes equal to that obtained with enzyme from ungerminated seed. Enzyme was inseparable from pigment by several other methods.